/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

package java.nio;

/**
 * A buffer for bytes.
 *
 * <p>A byte buffer can be created in either one of the following ways:
 *
 * <ul>
 *   <li>{@link #allocate(int) Allocate} a new byte array and create a buffer based on it;
 *   <li>{@link #allocateDirect(int) Allocate} a memory block and create a direct buffer based on
 *       it;
 *   <li>{@link #wrap(byte[]) Wrap} an existing byte array to create a new buffer.
 * </ul>
 *
 * @since Android 1.0
 */
public abstract class ByteBuffer extends Buffer
    implements Comparable<ByteBuffer>, StringToByteBuffer {

  /**
   * Creates a byte buffer based on a newly allocated byte array.
   *
   * @param capacity the capacity of the new buffer
   * @return the created byte buffer.
   * @throws IllegalArgumentException if {@code capacity < 0}.
   * @since Android 1.0
   */
  public static ByteBuffer allocate(int capacity) {
    if (capacity < 0) {
      throw new IllegalArgumentException();
    }
    return BufferFactory.newByteBuffer(capacity);
  }

  /**
   * Creates a direct byte buffer based on a newly allocated memory block.
   *
   * @param capacity the capacity of the new buffer
   * @return the created byte buffer.
   * @throws IllegalArgumentException if {@code capacity < 0}.
   * @since Android 1.0
   */
  public static ByteBuffer allocateDirect(int capacity) {
    if (capacity < 0) {
      throw new IllegalArgumentException();
    }
    return BufferFactory.newDirectByteBuffer(capacity);
  }

  /**
   * Creates a new byte buffer by wrapping the given byte array.
   *
   * <p>Calling this method has the same effect as {@code wrap(array, 0, array.length)}.
   *
   * @param array the byte array which the new buffer will be based on
   * @return the created byte buffer.
   * @since Android 1.0
   */
  public static ByteBuffer wrap(byte[] array) {
    return BufferFactory.newByteBuffer(array);
  }

  /**
   * Creates a new byte buffer by wrapping the given byte array.
   *
   * <p>The new buffer's position will be {@code start}, limit will be {@code start + len}, capacity
   * will be the length of the array.
   *
   * @param array the byte array which the new buffer will be based on.
   * @param start the start index, must not be negative and not greater than {@code array.length}.
   * @param len the length, must not be negative and not greater than {@code array.length - start}.
   * @return the created byte buffer.
   * @exception IndexOutOfBoundsException if either {@code start} or {@code len} is invalid.
   * @since Android 1.0
   */
  public static ByteBuffer wrap(byte[] array, int start, int len) {
    int length = array.length;
    if ((start < 0) || (len < 0) || (start + len > length)) {
      throw new IndexOutOfBoundsException();
    }

    ByteBuffer buf = BufferFactory.newByteBuffer(array);
    buf.position = start;
    buf.limit = start + len;

    return buf;
  }

  /** The byte order of this buffer, default is {@code BIG_ENDIAN}. */
  Endianness order = Endianness.BIG_ENDIAN;

  /**
   * Constructs a {@code ByteBuffer} with given capacity.
   *
   * @param capacity the capacity of the buffer.
   */
  ByteBuffer(int capacity) {
    super(capacity);
  }

  /**
   * Returns the byte array which this buffer is based on, if there is one.
   *
   * @return the byte array which this buffer is based on.
   * @exception ReadOnlyBufferException if this buffer is based on a read-only array.
   * @exception UnsupportedOperationException if this buffer is not based on an array.
   * @since Android 1.0
   */
  public final byte[] array() {
    return protectedArray();
  }

  /**
   * Returns the offset of the byte array which this buffer is based on, if there is one.
   *
   * <p>The offset is the index of the array which corresponds to the zero position of the buffer.
   *
   * @return the offset of the byte array which this buffer is based on.
   * @exception ReadOnlyBufferException if this buffer is based on a read-only array.
   * @exception UnsupportedOperationException if this buffer is not based on an array.
   * @since Android 1.0
   */
  public final int arrayOffset() {
    return protectedArrayOffset();
  }

  /**
   * Returns a char buffer which is based on the remaining content of this byte buffer.
   *
   * <p>The new buffer's position is zero, its limit and capacity is the number of remaining bytes
   * divided by two, and its mark is not set. The new buffer's read-only property and byte order are
   * the same as this buffer's. The new buffer is direct if this byte buffer is direct.
   *
   * <p>The new buffer shares its content with this buffer, which means either buffer's change of
   * content will be visible to the other. The two buffer's position, limit and mark are
   * independent.
   *
   * @return a char buffer which is based on the content of this byte buffer.
   * @since Android 1.0
   */
  public abstract CharBuffer asCharBuffer();

  /**
   * Returns a double buffer which is based on the remaining content of this byte buffer.
   *
   * <p>The new buffer's position is zero, its limit and capacity is the number of remaining bytes
   * divided by eight, and its mark is not set. The new buffer's read-only property and byte order
   * are the same as this buffer's. The new buffer is direct if this byte buffer is direct.
   *
   * <p>The new buffer shares its content with this buffer, which means either buffer's change of
   * content will be visible to the other. The two buffer's position, limit and mark are
   * independent.
   *
   * @return a double buffer which is based on the content of this byte buffer.
   * @since Android 1.0
   */
  public abstract DoubleBuffer asDoubleBuffer();

  /**
   * Returns a float buffer which is based on the remaining content of this byte buffer.
   *
   * <p>The new buffer's position is zero, its limit and capacity is the number of remaining bytes
   * divided by four, and its mark is not set. The new buffer's read-only property and byte order
   * are the same as this buffer's. The new buffer is direct if this byte buffer is direct.
   *
   * <p>The new buffer shares its content with this buffer, which means either buffer's change of
   * content will be visible to the other. The two buffer's position, limit and mark are
   * independent.
   *
   * @return a float buffer which is based on the content of this byte buffer.
   * @since Android 1.0
   */
  public abstract FloatBuffer asFloatBuffer();

  /**
   * Returns a int buffer which is based on the remaining content of this byte buffer.
   *
   * <p>The new buffer's position is zero, its limit and capacity is the number of remaining bytes
   * divided by four, and its mark is not set. The new buffer's read-only property and byte order
   * are the same as this buffer's. The new buffer is direct if this byte buffer is direct.
   *
   * <p>The new buffer shares its content with this buffer, which means either buffer's change of
   * content will be visible to the other. The two buffer's position, limit and mark are
   * independent.
   *
   * @return a int buffer which is based on the content of this byte buffer.
   * @since Android 1.0
   */
  public abstract IntBuffer asIntBuffer();

  /**
   * Returns a long buffer which is based on the remaining content of this byte buffer.
   *
   * <p>The new buffer's position is zero, its limit and capacity is the number of remaining bytes
   * divided by eight, and its mark is not set. The new buffer's read-only property and byte order
   * are the same as this buffer's. The new buffer is direct if this byte buffer is direct.
   *
   * <p>The new buffer shares its content with this buffer, which means either buffer's change of
   * content will be visible to the other. The two buffer's position, limit and mark are
   * independent.
   *
   * @return a long buffer which is based on the content of this byte buffer.
   * @since Android 1.0
   */
  public abstract LongBuffer asLongBuffer();

  /**
   * Returns a read-only buffer that shares its content with this buffer.
   *
   * <p>The returned buffer is guaranteed to be a new instance, even if this buffer is read-only
   * itself. The new buffer's position, limit, capacity and mark are the same as this buffer.
   *
   * <p>The new buffer shares its content with this buffer, which means this buffer's change of
   * content will be visible to the new buffer. The two buffer's position, limit and mark are
   * independent.
   *
   * @return a read-only version of this buffer.
   * @since Android 1.0
   */
  public abstract ByteBuffer asReadOnlyBuffer();

  /**
   * Returns a short buffer which is based on the remaining content of this byte buffer.
   *
   * <p>The new buffer's position is zero, its limit and capacity is the number of remaining bytes
   * divided by two, and its mark is not set. The new buffer's read-only property and byte order are
   * the same as this buffer's. The new buffer is direct if this byte buffer is direct.
   *
   * <p>The new buffer shares its content with this buffer, which means either buffer's change of
   * content will be visible to the other. The two buffer's position, limit and mark are
   * independent.
   *
   * @return a short buffer which is based on the content of this byte buffer.
   * @since Android 1.0
   */
  public abstract ShortBuffer asShortBuffer();

  /**
   * Compacts this byte buffer.
   *
   * <p>The remaining bytes will be moved to the head of the buffer, starting from position zero.
   * Then the position is set to {@code remaining()}; the limit is set to capacity; the mark is
   * cleared.
   *
   * @return this buffer.
   * @exception ReadOnlyBufferException if no changes may be made to the contents of this buffer.
   * @since Android 1.0
   */
  public abstract ByteBuffer compact();

  /**
   * Compares the remaining bytes of this buffer to another byte buffer's remaining bytes.
   *
   * @param otherBuffer another byte buffer.
   * @return a negative value if this is less than {@code other}; 0 if this equals to {@code other};
   *     a positive value if this is greater than {@code other}.
   * @exception ClassCastException if {@code other} is not a byte buffer.
   * @since Android 1.0
   */
  public int compareTo(ByteBuffer otherBuffer) {
    int compareRemaining =
        (remaining() < otherBuffer.remaining()) ? remaining() : otherBuffer.remaining();
    int thisPos = position;
    int otherPos = otherBuffer.position;
    byte thisByte, otherByte;
    while (compareRemaining > 0) {
      thisByte = get(thisPos);
      otherByte = otherBuffer.get(otherPos);
      if (thisByte != otherByte) {
        return thisByte < otherByte ? -1 : 1;
      }
      thisPos++;
      otherPos++;
      compareRemaining--;
    }
    return remaining() - otherBuffer.remaining();
  }

  /**
   * Returns a duplicated buffer that shares its content with this buffer.
   *
   * <p>The duplicated buffer's position, limit, capacity and mark are the same as this buffer's.
   * The duplicated buffer's read-only property and byte order are the same as this buffer's too.
   *
   * <p>The new buffer shares its content with this buffer, which means either buffer's change of
   * content will be visible to the other. The two buffer's position, limit and mark are
   * independent.
   *
   * @return a duplicated buffer that shares its content with this buffer.
   * @since Android 1.0
   */
  public abstract ByteBuffer duplicate();

  /**
   * Checks whether this byte buffer is equal to another object.
   *
   * <p>If {@code other} is not a byte buffer then {@code false} is returned. Two byte buffers are
   * equal if and only if their remaining bytes are exactly the same. Position, limit, capacity and
   * mark are not considered.
   *
   * @param other the object to compare with this byte buffer.
   * @return {@code true} if this byte buffer is equal to {@code other}, {@code false} otherwise.
   * @since Android 1.0
   */
  public boolean equals(Object other) {
    if (!(other instanceof ByteBuffer)) {
      return false;
    }
    ByteBuffer otherBuffer = (ByteBuffer) other;

    if (remaining() != otherBuffer.remaining()) {
      return false;
    }

    int myPosition = position;
    int otherPosition = otherBuffer.position;
    boolean equalSoFar = true;
    while (equalSoFar && (myPosition < limit)) {
      equalSoFar = get(myPosition++) == otherBuffer.get(otherPosition++);
    }

    return equalSoFar;
  }

  /**
   * Returns the byte at the current position and increases the position by 1.
   *
   * @return the byte at the current position.
   * @exception BufferUnderflowException if the position is equal or greater than limit.
   * @since Android 1.0
   */
  public abstract byte get();

  /**
   * Reads bytes from the current position into the specified byte array and increases the position
   * by the number of bytes read.
   *
   * <p>Calling this method has the same effect as {@code get(dest, 0, dest.length)}.
   *
   * @param dest the destination byte array.
   * @return this buffer.
   * @exception BufferUnderflowException if {@code dest.length} is greater than {@code remaining()}.
   * @since Android 1.0
   */
  public ByteBuffer get(byte[] dest) {
    return get(dest, 0, dest.length);
  }

  /**
   * Reads bytes from the current position into the specified byte array, starting at the specified
   * offset, and increases the position by the number of bytes read.
   *
   * @param dest the target byte array.
   * @param off the offset of the byte array, must not be negative and not greater than {@code
   *     dest.length}.
   * @param len the number of bytes to read, must not be negative and not greater than {@code
   *     dest.length - off}
   * @return this buffer.
   * @exception IndexOutOfBoundsException if either {@code off} or {@code len} is invalid.
   * @exception BufferUnderflowException if {@code len} is greater than {@code remaining()}.
   * @since Android 1.0
   */
  public ByteBuffer get(byte[] dest, int off, int len) {
    int length = dest.length;
    if ((off < 0) || (len < 0) || (len > length - off)) {
      throw new IndexOutOfBoundsException();
    }

    if (len > remaining()) {
      throw new BufferUnderflowException();
    }
    for (int i = off; i < off + len; i++) {
      dest[i] = get();
    }
    return this;
  }

  /**
   * Returns the byte at the specified index and does not change the position.
   *
   * @param index the index, must not be negative and less than limit.
   * @return the byte at the specified index.
   * @exception IndexOutOfBoundsException if index is invalid.
   * @since Android 1.0
   */
  public abstract byte get(int index);

  /**
   * Returns the char at the current position and increases the position by 2.
   *
   * <p>The 2 bytes starting at the current position are composed into a char according to the
   * current byte order and returned.
   *
   * @return the char at the current position.
   * @exception BufferUnderflowException if the position is greater than {@code limit - 2}.
   * @since Android 1.0
   */
  public abstract char getChar();

  /**
   * Returns the char at the specified index.
   *
   * <p>The 2 bytes starting from the specified index are composed into a char according to the
   * current byte order and returned. The position is not changed.
   *
   * @param index the index, must not be negative and equal or less than {@code limit - 2}.
   * @return the char at the specified index.
   * @exception IndexOutOfBoundsException if {@code index} is invalid.
   * @since Android 1.0
   */
  public abstract char getChar(int index);

  /**
   * Returns the double at the current position and increases the position by 8.
   *
   * <p>The 8 bytes starting from the current position are composed into a double according to the
   * current byte order and returned.
   *
   * @return the double at the current position.
   * @exception BufferUnderflowException if the position is greater than {@code limit - 8}.
   * @since Android 1.0
   */
  public abstract double getDouble();

  /**
   * Returns the double at the specified index.
   *
   * <p>The 8 bytes starting at the specified index are composed into a double according to the
   * current byte order and returned. The position is not changed.
   *
   * @param index the index, must not be negative and equal or less than {@code limit - 8}.
   * @return the double at the specified index.
   * @exception IndexOutOfBoundsException if {@code index} is invalid.
   * @since Android 1.0
   */
  public abstract double getDouble(int index);

  /**
   * Returns the float at the current position and increases the position by 4.
   *
   * <p>The 4 bytes starting at the current position are composed into a float according to the
   * current byte order and returned.
   *
   * @return the float at the current position.
   * @exception BufferUnderflowException if the position is greater than {@code limit - 4}.
   * @since Android 1.0
   */
  public abstract float getFloat();

  /**
   * Returns the float at the specified index.
   *
   * <p>The 4 bytes starting at the specified index are composed into a float according to the
   * current byte order and returned. The position is not changed.
   *
   * @param index the index, must not be negative and equal or less than {@code limit - 4}.
   * @return the float at the specified index.
   * @exception IndexOutOfBoundsException if {@code index} is invalid.
   * @since Android 1.0
   */
  public abstract float getFloat(int index);

  /**
   * Returns the int at the current position and increases the position by 4.
   *
   * <p>The 4 bytes starting at the current position are composed into a int according to the
   * current byte order and returned.
   *
   * @return the int at the current position.
   * @exception BufferUnderflowException if the position is greater than {@code limit - 4}.
   * @since Android 1.0
   */
  public abstract int getInt();

  /**
   * Returns the int at the specified index.
   *
   * <p>The 4 bytes starting at the specified index are composed into a int according to the current
   * byte order and returned. The position is not changed.
   *
   * @param index the index, must not be negative and equal or less than {@code limit - 4}.
   * @return the int at the specified index.
   * @exception IndexOutOfBoundsException if {@code index} is invalid.
   * @since Android 1.0
   */
  public abstract int getInt(int index);

  /**
   * Returns the long at the current position and increases the position by 8.
   *
   * <p>The 8 bytes starting at the current position are composed into a long according to the
   * current byte order and returned.
   *
   * @return the long at the current position.
   * @exception BufferUnderflowException if the position is greater than {@code limit - 8}.
   * @since Android 1.0
   */
  public abstract long getLong();

  /**
   * Returns the long at the specified index.
   *
   * <p>The 8 bytes starting at the specified index are composed into a long according to the
   * current byte order and returned. The position is not changed.
   *
   * @param index the index, must not be negative and equal or less than {@code limit - 8}.
   * @return the long at the specified index.
   * @exception IndexOutOfBoundsException if {@code index} is invalid.
   * @since Android 1.0
   */
  public abstract long getLong(int index);

  /**
   * Returns the short at the current position and increases the position by 2.
   *
   * <p>The 2 bytes starting at the current position are composed into a short according to the
   * current byte order and returned.
   *
   * @return the short at the current position.
   * @exception BufferUnderflowException if the position is greater than {@code limit - 2}.
   * @since Android 1.0
   */
  public abstract short getShort();

  /**
   * Returns the short at the specified index.
   *
   * <p>The 2 bytes starting at the specified index are composed into a short according to the
   * current byte order and returned. The position is not changed.
   *
   * @param index the index, must not be negative and equal or less than {@code limit - 2}.
   * @return the short at the specified index.
   * @exception IndexOutOfBoundsException if {@code index} is invalid.
   * @since Android 1.0
   */
  public abstract short getShort(int index);

  /**
   * Indicates whether this buffer is based on a byte array and provides read/write access.
   *
   * @return {@code true} if this buffer is based on a byte array and provides read/write access,
   *     {@code false} otherwise.
   * @since Android 1.0
   */
  public final boolean hasArray() {
    return protectedHasArray();
  }

  /**
   * Calculates this buffer's hash code from the remaining chars. The position, limit, capacity and
   * mark don't affect the hash code.
   *
   * @return the hash code calculated from the remaining bytes.
   * @since Android 1.0
   */
  public int hashCode() {
    int myPosition = position;
    int hash = 0;
    while (myPosition < limit) {
      hash = hash + get(myPosition++);
    }
    return hash;
  }

  /**
   * Indicates whether this buffer is direct.
   *
   * @return {@code true} if this buffer is direct, {@code false} otherwise.
   * @since Android 1.0
   */
  public abstract boolean isDirect();

  /**
   * Returns the byte order used by this buffer when converting bytes from/to other primitive types.
   *
   * <p>The default byte order of byte buffer is always {@link ByteOrder#BIG_ENDIAN BIG_ENDIAN}
   *
   * @return the byte order used by this buffer when converting bytes from/to other primitive types.
   * @since Android 1.0
   */
  public final ByteOrder order() {
    return order == Endianness.BIG_ENDIAN ? ByteOrder.BIG_ENDIAN : ByteOrder.LITTLE_ENDIAN;
  }

  /**
   * Sets the byte order of this buffer.
   *
   * @param byteOrder the byte order to set. If {@code null} then the order will be {@link
   *     ByteOrder#LITTLE_ENDIAN LITTLE_ENDIAN}.
   * @return this buffer.
   * @see ByteOrder
   * @since Android 1.0
   */
  public final ByteBuffer order(ByteOrder byteOrder) {
    return orderImpl(byteOrder);
  }

  ByteBuffer orderImpl(ByteOrder byteOrder) {
    order = byteOrder == ByteOrder.BIG_ENDIAN ? Endianness.BIG_ENDIAN : Endianness.LITTLE_ENDIAN;
    return this;
  }

  /**
   * Child class implements this method to realize {@code array()}.
   *
   * @see #array()
   * @since Android 1.0
   * @return byte array
   */
  abstract byte[] protectedArray();

  /**
   * Child class implements this method to realize {@code arrayOffset()}.
   *
   * @see #arrayOffset()
   * @since Android 1.0
   * @return int value
   */
  abstract int protectedArrayOffset();

  /**
   * Child class implements this method to realize {@code hasArray()}.
   *
   * @see #hasArray()
   * @since Android 1.0
   * @return boolean value
   */
  abstract boolean protectedHasArray();

  /**
   * Writes the given byte to the current position and increases the position by 1.
   *
   * @param b the byte to write.
   * @return this buffer.
   * @exception BufferOverflowException if position is equal or greater than limit.
   * @exception ReadOnlyBufferException if no changes may be made to the contents of this buffer.
   * @since Android 1.0
   */
  public abstract ByteBuffer put(byte b);

  /**
   * Writes bytes in the given byte array to the current position and increases the position by the
   * number of bytes written.
   *
   * <p>Calling this method has the same effect as {@code put(src, 0, src.length)}.
   *
   * @param src the source byte array.
   * @return this buffer.
   * @exception BufferOverflowException if {@code remaining()} is less than {@code src.length}.
   * @exception ReadOnlyBufferException if no changes may be made to the contents of this buffer.
   * @since Android 1.0
   */
  public final ByteBuffer put(byte[] src) {
    return put(src, 0, src.length);
  }

  /**
   * Writes bytes in the given byte array, starting from the specified offset, to the current
   * position and increases the position by the number of bytes written.
   *
   * @param src the source byte array.
   * @param off the offset of byte array, must not be negative and not greater than {@code
   *     src.length}.
   * @param len the number of bytes to write, must not be negative and not greater than {@code
   *     src.length - off}.
   * @return this buffer.
   * @exception BufferOverflowException if {@code remaining()} is less than {@code len}.
   * @exception IndexOutOfBoundsException if either {@code off} or {@code len} is invalid.
   * @exception ReadOnlyBufferException if no changes may be made to the contents of this buffer.
   * @since Android 1.0
   */
  public ByteBuffer put(byte[] src, int off, int len) {
    int length = src.length;
    if ((off < 0) || (len < 0) || (len > length - off)) {
      throw new IndexOutOfBoundsException();
    }

    if (len > remaining()) {
      throw new BufferOverflowException();
    }
    for (int i = off; i < off + len; i++) {
      put(src[i]);
    }
    return this;
  }

  /**
   * Writes all the remaining bytes of the {@code src} byte buffer to this buffer's current
   * position, and increases both buffers' position by the number of bytes copied.
   *
   * @param src the source byte buffer.
   * @return this buffer.
   * @exception BufferOverflowException if {@code src.remaining()} is greater than this buffer's
   *     {@code remaining()}.
   * @exception IllegalArgumentException if {@code src} is this buffer.
   * @exception ReadOnlyBufferException if no changes may be made to the contents of this buffer.
   * @since Android 1.0
   */
  public ByteBuffer put(ByteBuffer src) {
    if (src == this) {
      throw new IllegalArgumentException();
    }
    if (src.remaining() > remaining()) {
      throw new BufferOverflowException();
    }
    byte[] contents = new byte[src.remaining()];
    src.get(contents);
    put(contents);
    return this;
  }

  /**
   * Write a byte to the specified index of this buffer without changing the position.
   *
   * @param index the index, must not be negative and less than the limit.
   * @param b the byte to write.
   * @return this buffer.
   * @exception IndexOutOfBoundsException if {@code index} is invalid.
   * @exception ReadOnlyBufferException if no changes may be made to the contents of this buffer.
   * @since Android 1.0
   */
  public abstract ByteBuffer put(int index, byte b);

  /**
   * Writes the given char to the current position and increases the position by 2.
   *
   * <p>The char is converted to bytes using the current byte order.
   *
   * @param value the char to write.
   * @return this buffer.
   * @exception BufferOverflowException if position is greater than {@code limit - 2}.
   * @exception ReadOnlyBufferException if no changes may be made to the contents of this buffer.
   * @since Android 1.0
   */
  public abstract ByteBuffer putChar(char value);

  /**
   * Writes the given char to the specified index of this buffer.
   *
   * <p>The char is converted to bytes using the current byte order. The position is not changed.
   *
   * @param index the index, must not be negative and equal or less than {@code limit - 2}.
   * @param value the char to write.
   * @return this buffer.
   * @exception IndexOutOfBoundsException if {@code index} is invalid.
   * @exception ReadOnlyBufferException if no changes may be made to the contents of this buffer.
   * @since Android 1.0
   */
  public abstract ByteBuffer putChar(int index, char value);

  /**
   * Writes the given double to the current position and increases the position by 8.
   *
   * <p>The double is converted to bytes using the current byte order.
   *
   * @param value the double to write.
   * @return this buffer.
   * @exception BufferOverflowException if position is greater than {@code limit - 8}.
   * @exception ReadOnlyBufferException if no changes may be made to the contents of this buffer.
   * @since Android 1.0
   */
  public abstract ByteBuffer putDouble(double value);

  /**
   * Writes the given double to the specified index of this buffer.
   *
   * <p>The double is converted to bytes using the current byte order. The position is not changed.
   *
   * @param index the index, must not be negative and equal or less than {@code limit - 8}.
   * @param value the double to write.
   * @return this buffer.
   * @exception IndexOutOfBoundsException if {@code index} is invalid.
   * @exception ReadOnlyBufferException if no changes may be made to the contents of this buffer.
   * @since Android 1.0
   */
  public abstract ByteBuffer putDouble(int index, double value);

  /**
   * Writes the given float to the current position and increases the position by 4.
   *
   * <p>The float is converted to bytes using the current byte order.
   *
   * @param value the float to write.
   * @return this buffer.
   * @exception BufferOverflowException if position is greater than {@code limit - 4}.
   * @exception ReadOnlyBufferException if no changes may be made to the contents of this buffer.
   * @since Android 1.0
   */
  public abstract ByteBuffer putFloat(float value);

  /**
   * Writes the given float to the specified index of this buffer.
   *
   * <p>The float is converted to bytes using the current byte order. The position is not changed.
   *
   * @param index the index, must not be negative and equal or less than {@code limit - 4}.
   * @param value the float to write.
   * @return this buffer.
   * @exception IndexOutOfBoundsException if {@code index} is invalid.
   * @exception ReadOnlyBufferException if no changes may be made to the contents of this buffer.
   * @since Android 1.0
   */
  public abstract ByteBuffer putFloat(int index, float value);

  /**
   * Writes the given int to the current position and increases the position by 4.
   *
   * <p>The int is converted to bytes using the current byte order.
   *
   * @param value the int to write.
   * @return this buffer.
   * @exception BufferOverflowException if position is greater than {@code limit - 4}.
   * @exception ReadOnlyBufferException if no changes may be made to the contents of this buffer.
   * @since Android 1.0
   */
  public abstract ByteBuffer putInt(int value);

  /**
   * Writes the given int to the specified index of this buffer.
   *
   * <p>The int is converted to bytes using the current byte order. The position is not changed.
   *
   * @param index the index, must not be negative and equal or less than {@code limit - 4}.
   * @param value the int to write.
   * @return this buffer.
   * @exception IndexOutOfBoundsException if {@code index} is invalid.
   * @exception ReadOnlyBufferException if no changes may be made to the contents of this buffer.
   * @since Android 1.0
   */
  public abstract ByteBuffer putInt(int index, int value);

  /**
   * Writes the given long to the current position and increases the position by 8.
   *
   * <p>The long is converted to bytes using the current byte order.
   *
   * @param value the long to write.
   * @return this buffer.
   * @exception BufferOverflowException if position is greater than {@code limit - 8}.
   * @exception ReadOnlyBufferException if no changes may be made to the contents of this buffer.
   * @since Android 1.0
   */
  public abstract ByteBuffer putLong(long value);

  /**
   * Writes the given long to the specified index of this buffer.
   *
   * <p>The long is converted to bytes using the current byte order. The position is not changed.
   *
   * @param index the index, must not be negative and equal or less than {@code limit - 8}.
   * @param value the long to write.
   * @return this buffer.
   * @exception IndexOutOfBoundsException if {@code index} is invalid.
   * @exception ReadOnlyBufferException if no changes may be made to the contents of this buffer.
   * @since Android 1.0
   */
  public abstract ByteBuffer putLong(int index, long value);

  /**
   * Writes the given short to the current position and increases the position by 2.
   *
   * <p>The short is converted to bytes using the current byte order.
   *
   * @param value the short to write.
   * @return this buffer.
   * @exception BufferOverflowException if position is greater than {@code limit - 2}.
   * @exception ReadOnlyBufferException if no changes may be made to the contents of this buffer.
   * @since Android 1.0
   */
  public abstract ByteBuffer putShort(short value);

  /**
   * Writes the given short to the specified index of this buffer.
   *
   * <p>The short is converted to bytes using the current byte order. The position is not changed.
   *
   * @param index the index, must not be negative and equal or less than {@code limit - 2}.
   * @param value the short to write.
   * @return this buffer.
   * @exception IndexOutOfBoundsException if {@code index} is invalid.
   * @exception ReadOnlyBufferException if no changes may be made to the contents of this buffer.
   * @since Android 1.0
   */
  public abstract ByteBuffer putShort(int index, short value);

  /**
   * Returns a sliced buffer that shares its content with this buffer.
   *
   * <p>The sliced buffer's capacity will be this buffer's {@code remaining()}, and it's zero
   * position will correspond to this buffer's current position. The new buffer's position will be
   * 0, limit will be its capacity, and its mark is cleared. The new buffer's read-only property and
   * byte order are the same as this buffer's.
   *
   * <p>The new buffer shares its content with this buffer, which means either buffer's change of
   * content will be visible to the other. The two buffer's position, limit and mark are
   * independent.
   *
   * @return a sliced buffer that shares its content with this buffer.
   * @since Android 1.0
   */
  public abstract ByteBuffer slice();

  /**
   * Returns a string representing the state of this byte buffer.
   *
   * @return a string representing the state of this byte buffer.
   * @since Android 1.0
   */
  public String toString() {
    StringBuffer buf = new StringBuffer();
    buf.append(getClass().getName());
    buf.append(", status: capacity="); // $NON-NLS-1$
    buf.append(capacity());
    buf.append(" position="); // $NON-NLS-1$
    buf.append(position());
    buf.append(" limit="); // $NON-NLS-1$
    buf.append(limit());
    return buf.toString();
  }

  public ByteBuffer stringToByteBuffer(String s) {
    return new java.nio.StringByteBuffer(s);
  }
}
